The Smoot-Hawley Tariff Act of 1930 set high tariffs on hundreds of products. Today, many of the tariffs from this act have been reduced or even eliminated. One exception is the tariff rate of 48% on sneakers imported into the United States. If the Smoot-Hawley tariff on imported sneakers was repealed, you would expect:

Currently most sneakers (and any other type of shoes) are imported, with most of them coming from Asian countries like China, Vietnam, Indonesia, etc. Some firms still produce sneakers domestically, but they represent a very small portion of total sales since major brands like Nike, Adidas, Reebok, etc. basically import them all

If the tariffs set on sneakers disappeared, the few remaining brands produced in the US would probably cease domestic production. Domestic factories would close and jobs will be lost. But not everything should be necessarily bad, since the price of sneakers could lower. It doesn't mean that they will decrease by 48% or anything close to it.

Actual production costs represent only a small percentage of the sales price of most major sneaker manufacturers, e. g. Nike's shoes only cost a couple of dollars to make in Asia and they are sold at much higher prices. The tariffs are paid according to import values which are very low, so any decrease in price would be of only a few dollars (if any at all).

That is probably the reason why that tariff still remains in place, because the potential harms are larger than the potential benefits.